The magnitude and urgency of the challenges facing agriculture and food systems demand profound modifications in different aspects of human activity to achieve real transformative change and sustainability. Recognizing that the inherent complexity of achieving sustainability is commonly seen as a deterrent to decision-making, the Food and Agriculture Organization of the United Nations (FAO) has approved the 10 Elements of Agroecology as an analytical framework to support the design of differentiated paths for agriculture and food systems transformation, hence facilitating improved decision-making by policymakers, practitioners and other stakeholders in differing contexts at a range of levels on a number of scales. Biodiversity, consumers, education and governance are identified as promising entry points to build a structured process using visual narratives that rely on the 10 Elements of Agroecology to graphically dissect prospective social-ecological transition trajectories. We illustrate such applications with examples from agroforestry worldwide, public food procurement in Brazil and the United States of America, and agroecology education vis-à-vis secure access to land in Senegal. Nexus approaches are used to highlight and examine salient interactions among different sectors and entry points, and to develop visual narratives describing plausible theories of transformative change towards sustainable agriculture and food systems.

There is increasing interest in agroecology as a way to move toward more sustainable agriculture and food systems. However, the evidence of agroecology's contribution to sustainability remains fragmented because of heterogeneous methods and data, differing scales and timeframes, and knowledge gaps. Facing these challenges, 70 representatives of agroecology-related organizations worldwide participated in the development of the Tool for Agroecology Performance Evaluation (TAPE), to produce and consolidate evidence on the multidimensional performances of agroecological systems. TAPE is composed of: Step 0, the preliminary step that includes a description of the main socio-economic and demographic characteristics of the agricultural and food systems and an analysis of the enabling environment in terms of relevant policy, market, technology, socio-cultural and/or historical drivers; Step 1, the Characterization of Agroecological Transitions (CAET), based on the 10 Elements of Agroecology adopted by FAO and its member countries, using descriptive scales to establish scores and assessing the degree of transition, with information from the farm/household and community/territory scale; Step 2, the Core Criteria of Performance listing the key dimensions considered relevant to address the Sustainable Development Goals (SDGs): Environment & climate change; Health & nutrition; Society & culture; Economy and Governance. Finally Step 3, a participatory validation of the results obtained from the previous steps with the producers and relevant stakeholders. TAPE can be used (i) to assess the extent of agroecological transition among agricultural producers in a community or a territory, (ii) to monitor and evaluate projects by characterizing the initial and subsequent steps in an agroecological transition, and/or (iii) to evaluate widely diverse agricultural systems against agroecological elements and how they contribute to the achievement of the SDGs. Its application can support the transition of all forms of agricultural systems toward more sustainable practices and the formulation of adequate policies to enable this transformation. Preliminary results from pilot applications show that TAPE can perform in a variety of geographic regions and agroecosystems and that it allows assessment of performances of various criteria that move beyond classic indicators to begin to build a global evidence base for agroecology and support transformation to sustainable agricultural production and food systems.

Canada thistle is a perennial spreading weed that is difficult to control in farming systems with reduced reliance upon herbicides for weed management. Experiments were conducted from 2006 to 2008 at Champaign, IL, to evaluate the combined effects of summer annual cover crops and mowing on Canada thistle growth and survival. Whole plot treatments were fallow, buckwheat, sudangrass–cowpea mixture (MIX), and sudangrass. The subplot treatments were mowing frequencies (0 to 2 times). Cover crop and mowing did not interact to suppress Canada thistle. MIX and sudangrass produced more standing biomass, greater regrowth, and more surface mulch following mowing than the buckwheat. A single season with sudangrass or MIX reduced Canada thistle shoot density and mass to less than 20% of the initial values through two growing seasons. Mowing alone only suppressed Canada thistle shoot density and mass on the site with greater initial density. A sudangrass or MIX cover crop alone or combined with mowing suppresses Canada thistle, but intensive management must continue for several years to eliminate patches.

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The laminar scales of the fern Elaphoglossum paleaceum were studied to determine if they act as a morphological mechanism to protect leaves from excess light. We hypothesized that if scales serve this purpose, then individual plants growing in high light would have greater laminar scale density than those in low light. For our first experiment, plants from high light roadsides were collected and subjected to artificial scale removal and then exposed to super-saturating pulse of light for 30 min. We found that leaves with their scales removed exhibited significantly greater photoinhibition than leaves with scales intact. Leaves with intact scales recovered fully after twelve hours whereas those with scales removed remained photoinhibited. Scale density on the adaxial side of leaves was positively correlated with light intensity. The data from this study indicate that fern laminar scales help redu[:e photoinhibition and potentially function as a morphological defense against photodamage.The function of leaf vestiture has long been a hotanical curiosity. Apart from their utility for taxonomic purposes, leaf hairs and scales play many roles that directly influence plant physiology (

Changes in seed viability over 12 months of low-input storage conditions were monitored on five diverse seed species grown in the tropics: amaranth (Amaranthus cruentus), lablab bean (Lablab purpureus), moringa (Moringa oleifera), pumpkin (Cucurbita moschata) and tomato (Solanum lycopersicum). Because the costs of maintaining lowtemperature storage can be prohibitively expensive in developing countries, this study explored alternatives to low-temperature storage at the Educational Concerns for Hunger Organization (ECHO) Asia Impact Center Seed Bank in Northern Thailand. Specifically, this research compared the effects of vacuum sealing and refrigeration on stored seed viability in both laboratory and field settings. While seed species was an influential factor in determining seed longevity, the relative importance of vacuum sealing and refrigeration differed for the dependent variables of seed moisture content, germination rate, mean time to 50% germination and field emergence. Although the combination of vacuum sealing and refrigeration was most effective at conserving seed quality as measured by each of these variables, the storage of seeds in vacuum-sealed packages at ambient temperatures was more effective than unsealed but refrigerated packets at conserving low moisture content and high germination and field emergence rates across species. This suggests that for resource-constrained seed banks in the tropics, vacuum sealing with or without refrigeration may represent a viable alternative to other expensive and energy-intensive storage techniques.

Canada thistle is difficult to manage in organic farming systems and others with reduced reliance on herbicides. Previous field studies found that defoliation or sudangrass interference suppressed Canada thistle. Our objective was to understand the factors causing suppression of Canada thistle observed in the field. Three greenhouse studies were conducted utilizing frequency of defoliation, sudangrass interference and defoliation, and interspecific phytotoxicity to discern mechanisms of Canada thistle suppression. Increased defoliation frequency (up to four defoliations) decreased Canada thistle shoot height, shoot and root mass, and root-to-shoot ratio. Plants with larger root mass had greater shoot mass and number (r= 0.87 and 0.73, respectively), indicating a probable interdependence of root size (carbohydrate reserves), bud density, and subsequent shoot growth. In the sudangrass interference and defoliation study, Canada thistle shoot dry mass was 38.7, 2.76, and 0.39 g pot−1in the defoliation only, sudangrass interference only, and defoliation + interference + surface mulch treatments, respectively. Sudangrass interference by itself was effective in suppressing thistle growth; combining interference with defoliation did not further reduce growth (2.76 and 2.83 g pot−1, respectively). In the experiment minimizing interspecific competition, we found no evidence of sudangrass having a phytotoxic effect on Canada thistle. Overall results indicate that sudangrass competition or frequent shoot removal suppresses growth of Canada thistle.